Lighting, glass and color play a part making this two room apartment feel larger.
3) Color counts. If you can keep the largest pieces in the same tone as the walls, they will blend in and make a room feel wider. Lighter colors do tend to make spaces look larger, although breaking that 'rule' works if other elements - lighting, scale, and accents - help the eye travel around a space. Monochromatic schemes in neutral colors work well, adding back an accent hue to draw attention to points around the room.
4) Raise things up. Even if your ceilings are only 8' high, there are several tricks to give the illusion of height in a room. Place window coverings above the windows so they seem taller. Use moldings and other architectural elements to raise the eye up - a crown, medallions for hanging fixtures, tall shelves to the ceiling. Hang light fixtures slightly higher, and do the same with artwork.
5) Make things function well. Need a desk, a table, some storage? Find or make a piece that performs all three functions and save space. In dorms and apartments, a work desk usually becomes a dining table, and placed on a wall - possibly perpendicular - allows you to add shelving for books and office 'stuff' and still make the desk feel like a table. When looking for ways to divide a space - say the bed area from the sofa area - use open shelving that can house a TV, lighting, decorative and functional items, and look good doing so. Console tables can make ideal desks, and even dining tables. Backed up to an open backed sofa, creates a great dining area with instant seating. Using benches for seating around tables adds storage for quick access.